添加装饰:
recyclerView.addItemDecoration(new DividerItemDecoration(this, LinearLayout.VERTICAL));
recyclerView.addItemDecoration(new LeftDividerItemDecorator(this));
左分隔项装饰器的声明:
public class LeftDividerItemDecorator extends RecyclerView.ItemDecoration {
private final Drawable mDivider;
private final Rect mBounds = new Rect();
private final Context mContext;
LeftDividerItemDecorator(Context context) {
mContext = context;
mDivider = context.getResources().getDrawable(R.drawable.divider);
}
public void onDraw(@NonNull Canvas c, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
if (parent.getLayoutManager() != null && mDivider != null) {
drawLeftDivider(c, parent);
}
}
private void drawLeftDivider(Canvas canvas, RecyclerView parent) {
canvas.save();
int childCount = parent.getChildCount();
for (int i = 0; i < childCount; ++i) {
View child = parent.getChildAt(i);
parent.getDecoratedBoundsWithMargins(child, mBounds);
int childAdapterPosition = parent.getChildAdapterPosition(child);
int left = parent.getPaddingLeft();
// Solid size according to divider.xml width
//int right = left + (mDivider.getIntrinsicWidth());
// Dynamic size according to divider.xml width multiplied by child number
int right = left + (mDivider.getIntrinsicWidth() * (childAdapterPosition + 1));
int top = child.getTop();
int bottom = child.getBottom();
// Draw left vertical divider
mDivider.setBounds(
left,
top,
right,
bottom
);
mDivider.draw(canvas);
}
canvas.restore();
}
// Handles dividers width - move current views to right
public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
if (mDivider == null) {
outRect.set(0, 0, 0, 0);
} else {
int childAdapterPosition = parent.getChildAdapterPosition(view);
outRect.set(mDivider.getIntrinsicWidth() * childAdapterPosition, 0, 0, 0);
}
}
}
分隔符的 xml:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<size
android:width="4dp"
android:height="4dp" />
<solid android:color="@color/colorAccent" />
</shape>
Preview: